Seismic performance of a new type of prefabricated bridge pier with cast-in-place UHPC jacketing

Accelerated bridge construction (ABC) is prevalent all over the world attributable to its technical advantages including the higher construction efficiency, less traffic disruption, and higher construction quality. Grouting sleeves (GS) and grouting corrugated pipes (GCP) are the traditional connection methods of ABC in high seismic regions, with the disadvantages of uncompacted grouting and high requirement of construction accuracy. To this end, this paper developed a new type of prefabricated concrete bridge pier connected with ultra-high performance concrete (PCBP-UHPC) jacketing to solve the problems. To validate the seismic performance of the proposed innovative bridge pier, quasi-static tests on three full-scale specimens PCBP-UHPC, PCBP-GS, and PCBP-GCP were carried out. The results indicated that the failure mode of specimen PCBP-UHPC was similar to that of specimens PCBP-GS and PCBP-GCP with the characteristics of longitudinal steel yielding and concrete crushing at the base of the hollow pier. The obvious plastic hinge outward shifting could be observed during the loading for specimen PCBP-UHPC. The positive ultimate load of specimen PCBP-UHPC was 636.33 kN, which was 14.8% and 13.3% higher than those of specimens PCBP-GS and PCBP-GCP, respectively. In addition, a refined finite element model (FEM) was established by ABAQUS to provide an in-depth understanding on the failure mechanism of the proposed PCBP-UHPC. The parametric analyses were conducted to reveal the influence of the socket depth and axial compression ratio on seismic performance of the proposed PCBP-UHPC. The results indicated that the socket depth had little effect on seismic performance of the prefabricated pier, while the ultimate load bearing capacity of specimen PCBP-UHPC increased to some extent as the increase of the axial compression ratio. The present research work provides an innovative prefabricated bridge pier and a comprehensive experimental-numerical understanding on its seismic performance, which is beneficial for its engineering application.